Device for processing dentures



Feb. 9, 1937. c. M. ANDREWS DEVICE FOR PROCESSING DENTURES Filed March 24, 1954 2 Sheets-Sheet 1 M A w \u 0 m 4 m u/O m w w m Ill" m C.M.Andrews Feb. 9, 1937. c. M. ANDREWS DEVICE FOR PROCESSING DEN'IURES 2 Sheets-Sheet 2 Fileyl March 24, 1934 .vt w n e v (Ittorneg Patented Feb. 9, 1937 UNETED STATES PATENT OFFICE 3 Claims.

This invention relates to the dental art and more particularly to a method and means of and for moulding dentures to fit mouths of individual users thereof.

An object of the invention is the provision of a device so arranged that it is adapted for the preparation of all known denture plate materials, said device so arranged that certain denture material matrices, requiring the same, may be subjected to a preliminary dehydration.

Another object of the invention is to provide a method and means for applying a uniform degree of dry heat simultaneously to all parts of a denture during the formation thereof, whereby the denture upon being removed from its mould will retain its original contour imparted by said mould subsquent to a removal from the latter and upon contacting with a different temperature such as that of the atmosphere or mouth particularly when a denture is formed of phenol resinous compounds or the like.

A further object of the invention is to provide means for accurate temperature readings of dentures during the formation thereof and means for checking the said reading of one temperature indicating instrument against two other instruments, said instruments being different with respect to each other.

An important object of the invention is to provide means for and the elimination of the step of forming dentures by a preliminary heating thereof in the presence of boiling water by placing the dentures and their matrices directly in an operating chamber, in instances where certain denture materials may be advantageously so treated, the said means to be susceptible of adjustment and adapted for use in conjunction with certain other denture materials that lend themselves to an advantageous working with moisture.

A still further object of the invention is to provide a method and means whereby dentures may be formed perfectly and insuring a perfect fit in the mouth of a patient.

Another object of the invention is to provide a method and means of and for forming dentures which is economical in operation and practice and susceptible of adjustment for providing a correct and selected degree of heat for forming dentures while simultaneously applying mechanically generated pressure to the dentures in instances where the same is desired and in accordance with the denture material operated upon, the

said heat being variable, if desired, or being constantly maintained.

Other and further objects and advantages of the invention will be understood from the following detailed description thereof reference being had to the accompanying drawings, in which:

Figure 1 is a vertical section of the new apparatus constructed in accordance with a preferred embodiment of the invention.

Figure 2 is a transverse section thereof taken on the line 22 of Figure 1.

Figure 3 is a sectional View of a needle valve employed. 10

Figure 4 is a vertical section of a diaphragm valve.

Figure 5 is a side elevation of the apparatus.

Figure 6 is a top plan view thereof, and t Figure 7 is a vertical section of a funnel-valve employed.

Referring now to the drawings for a more particular description It designates generally a denture apparatus which includes a boiler I I having an outer wall I2, an inner wall I3, the said 2 walls being spaced from each other providing a water receptacle indicated at I4.

The boiler is preferably cylindrical. The outer walls I2 are provided with a bottom I5, the inner walls I3 being similarly equipped. The bottom 25 members I3 and I5 are spaced from each other an adequate distance and reinforced by means of stay bolts I6.

The outer wall I2 extends below the bottom member I5 providing a skirt H, the latter having 30 a plurality of apertures I8 for draft purposes as later explained. The outer wall is peened inwardly adjacent its top and joined with the inner wall as at I9, the inner wall projecting above said junction as at 20 providing an annular edge.

The boiler may be supported by any suitable means such as the legs 2|. The foregoing men-v tioned boiler parts are preferably welded together whereby a normally steam-tight boiler is pro- 40 vided which may be carried by the legs 2|. As best shown in Figure l, the boiler is provided with an elongated recess 22 which is adapted to be closed by means of a lid 23 for providing a selectively air-tight chamber.

An annular groove 24 is provided upon the lower face of the lid 23 and adapted to receive the upwardly projecting portion 20 of the inner wall of the boiler, said groove preferably being provided with a gasket 25. I

The lid is adapted to be clamped to the boiler by any suitable means such as by the transversely disposed bars 26 placed upon the top of the lid and the securing thereof by means of links 21 p0- sitioned at the ends of the bars.

The links are provided with hooks 28 at their lower ends which are adapted to member with a detent such as the annularly disposed hook '29 carried upon the outer wall l2 of the boiler and secured thereto by means of welding or the like. The upper ends of the links are provided with threads adapted to member with nuts 38 for clamping the cover lid to the boiler. As suggested by means of the dotted line representation thereof, in Figure 5, set screws 3| may be provided, if desired, upon the transversely disposed bars 26 and adapted to exert a downward pressure upon the lid for further urging the latter into a closed position.

It will be understood that in operation sufficient pressure may be applied to the lid, at desired times, for expanding the gasket 25 and sealing the chamber. The lid carries a cradle 32 preferably comprised of a plurality of downwardly extending bolts 33 threadedly secured to the lid, the lower ends thereof being provided with nuts or keepers 34 for supporting a transversely positioned seat 35, the bolts 33 extending through the latter, as best shown in Figure 2.

Centrally of the lid 23 an interiorly threaded shaft guide 33 is provided which may be formed integral with the lid, the upper end thereof being provided with suitable packing, not shown, and a packing nut 31. A rotatable shaft 38 extends through the guide 39 and is provided with threads adapted to member with the threads of the guide, the threads of the shaft extending substantially from its lower end half way its length, whereby the shaft may be raised and lowered by means of a wrench 38 carried at its upper end. It will be understood that the upper half portion of the shaft 38 is smooth for, facilitating the packing nut 3'1, providing a steam tight closure while permitting vertical rotary movements of the shaft, the threads of the latter not membering with the packing.

The lower end of the shaft terminates in a ball 39 adapted to member with a socket 40 carried by a foot 41 The shaft is also provided with an annular groove 42 adapted to receive a set screw 43 for securing the foot to the shaft in a manner whereby the foot may have slight vertifor preventing horizontal rotary movements of the foot, the wall of the aperture being of greater diameter than the bolt for permitting said swinging movements.

As best shown in Figure 1, the lid 23 carries a thermometer 46, the lower end thereof extending beyond the lid a. distance whereby, preferably, it is positioned substantially mid-way of the length of the inner wall [3 of the boiler at times when a chamber is provided by seating the lid on the boiler.

The recess-chamber 22 is provided with a vent opening normally closed by means of a pet-cock 4'! carried by the lid. The lid is further provided with an aperture 48 which is adapted to receive a pin 49 secured to and projecting above the boiler comprising a means for positioning the lid in the same position with respect to the boiler during repeated removals and replacements of the lid and preventing rotary. movements thereof.

I At desired times a communication may be established between the interior of the boiler and the chamber 22 by rotating and moving a needle valve 50 away from its seat 5! whereby a pas- -supported by a pipe 6|.

sageway 52 is provided, one end of the latter being in communication with the chamber 22 and the opposite end thereof being in communication with the interior of the boiler.

The boiler is provided with a pressure gauge 53, a safety blow-oil valve 54 and an air release duct or pipe 55, the latter being in communication with the interior of the boiler and normally closed by means of a cock 56.

A furnace 5'! is positioned under the bottom of the boiler for supplying heat to the apparatus, gas preferably being employed which is. conducted to the furnace 51 forming a source of supply, not

shown, through a pipe, duct or flexible hose 58.

passes through the duct 58 to the burner 51 .for a the overall purposes later mentioned. A cutoff cock is provided between the valve 59 and said source of fuel supply. The diaphragm valve includes a three part housing having a plate 60 The plate is provided with a flange B2 to which is secured a cover 63, the latter having a bushing 64 provided with annular threads upon its interior wall. A rotatable valve seat 55 is threadedly carried by the bushing 64 and provided with a hollow projecting por- I with the burner 51, is adapted to be closed by means of the valve 69. The flexible disc 61 prevents communication between the pipe 6| and the outlet port 10.

A valve The pipe 8| which carries the diaphragm valve I 59 is in communication with the interior of the boiler through a pipe H which extends outward- 1y from and upwardly of the boiler and terminates at a selected distance with respect to the height of the boiler for filling the latter with water to a desired extent.

As best shown in Figure 7, the pipe II is provided with a nipple for supporting a funnel valve 12. The funnel '12 is provided with a threaded neck 13 which is adapted to member with the threads of the nipple 14. The walls of the neck 13 are provided with transversely disposed apertures 15 through which water may pass for a passage to theinterior of the boiler at times when the funnel valve is in a raised position.

It will be understood that the funnel valve is adapted to close the pipe II in a fluid-tight manher by rotating the funnel until the co-nically shaped valve 16 thereof is snugly positioned against its seat 11, at times when the boiler is provided with water through the funnel as above described, the pet cook 56 carried by the. pipe 55 at the top of the boiler is opened for permitting air to pass therethrough.

As shown in Figure 1, a two part flask 18 is adapted to be carried upon the seat 35 of the cradle 32. The flask is made of metal and in-. cludes a lower receptacle 19, an upper sleeve 80 and a cover 8|. Within the receptacle [9 a lower matrix 82 is positioned and the sleeve provided with an upper matrix 83. Between the plaster of Paris matrices a denture 84 is. positioned.

The apparatus is adapted tocure and mold dentures of several compositions of matter which require for their proper treatment a different adjustment of the apparatus, said compositions include pyroxylin, vinyl-resin, phenol-formaldehyde, camphor, bakelite and vulcanite-rubber, of said compositions the vinyl-resin composition having been recently introduced to the dental profession.

In operation assuming that the denture 84 is of a composition which includes vulcanite rubber the molding thereof into a denture is as follows:

A flask, such as that shown in Figure l, is first prepared containing matrices of the denture to be molded and placed directly in the chamber formed by closing the lid of the latter, the pet cock 4'! being open at this time. The needle valve 59 being initially closed for a subsequent opening thereof for permitting a communication between the chamber 22 and the interior of the boiler, the valve 59 is regulated so that its valve-member 69 is spaced from its seat 65 an adequate distance for providing preferably substantially 280 degrees Fahrenheit of heat for the chamber 22 and at this time the pet cook 41 is closed after observing that steam exudes through it, said steam generating from the then moisture laden plaster of Paris matrices and not from the water jacket of the boiler.

The said denture material is treated for substantially 10 minutes preferably at said temperature. The foot 4| is then lowered upon the flask and the latter compressed until its two half portions can yield no further toward each other, and at this time the needle valve is opened permitting moisture to enter the chamber 22, the diaphragm valve 59 is next regulated for increasing the heat gradually until a vulcanizing temperature of substantially 320 degrees Fahrenheit of heat is applied to the said denture material and the latter amount of heat is maintained for preferably substantially minutes at which time the denture is removed subsequent to closing the needle valve 50 and opening the pet cock 1 allowing steam to escape, it should be noted that the denture should not be removed except at atmospheric pressure and after becoming cool.

The herein specifically described and illustrated mechanism is particularly well adapted for facilitating practicing of the herein described method, the primary and essential steps of the process includes providing in a flask matrices of the denture to be formed having therebetween the component parts of the denture, the latter including any one of the foregoing mentioned compositions of matter used in conjunction with teeth of porcelain or the like set in a removable binder of beeswax. A further essential step is placing the thus prepared flask directly in a chamber such as the chamber provided by the recess 22 in conjunction with the lid 23 therefor, whereby a chamber is provided. The step of directly placing the prepared flask in the chamber eliminates a heretofore practiced and now unnecessary step in such operations which included first placing the flask and contents in a container of boiling water with attendant undesirable results as later mentioned herein. The final essential step is subjecting the denture to a pressure and temperature suflicient to cause it to assume and retain the contour of its individual matrices with the teeth properly arranged. The said matrices being primarily provided by means of taking plaster cast impressions of a mouth with which the finished denture members are to be used.

An advantage derived from the use of the present invention and practicing the present method is placing the prepared flask directly in the chamber to the exclusion of a preliminary heating of the flask and contents in the presence of boiling water which not only saves said unnecessary step, but also insures better results in that the said old unnecessary step was conducive to forming imperfect dentures, the half portions of the flask having been locked together and pressure applied thereto in the water process the same did not provide an adequate degree of heat for softening the denture material properly. Pressure applied to the flask in the water process caused the porcelain teeth of the denture to often be impressed into the plaster of Paris matrix slightly whereby an imperfect fitting denture resulted. It being appreciated that the fitting of a denture to at least one thousandth of an inch of perfection is essentially a desideratum. Also due to the boiling water the plaster of Paris matrices became softened thereby permitting the forcing of the teeth thereinto as above mentioned; whereas, in the present method the plaster of Paris is in a comparatively dry, hard condition, which not only prevents the teeth from being formed into the matrices but prevents the latter from distortion, it being understood that wet plaster of Paris is more fragile or soft than when dry. flask directly in the chamber a greater degree of heat than that of the boiling temperature of water is provided for softening the denture material prior to and during the application of pressure for forcing the material to assume accurately the contour of an individual mould. By means of said step of placing the flask directly into a chamber substantially about 100 degrees of heat higher temperature than that of boiling water is utilized and applied to the denture and flask, said higher degree of heat being adequate for forming a perfect denture without altering the contour of plaster of Paris matrices.

Assuming that the denture 84 is of a composition which includes vinyl-resin material the molding thereof into a denture is as follows:

The matrices and flask must first be dehydrated or dried out to an adequate degree and for this purpose the same are placed in the chamber, the denture forming material initially being omitted, the pet cock 4! is open permitting moisture laden air to exude therefrom, the furnace supplying heat for heating the recess-chamber 22, the needle valve 50 being closed.

Preferably substantially 280 degrees Fahrenheit of heat is applied to the flask and matrices by adjusting the diaphragm valve 59 for regulating the furnace 51 and heating the boiler for applying the selected amount of heat to the flask, said degree of heat corresponding with the degree of heat at which the denture forming material 84 is to be ultimately molded, the preferred degreeof heat for the matrices and material respectively being substantially equivalent.

After the flask and matrices are adequately dehydrated the same are removed and the denture forming material placed therein and the flask repositioned in the chamber, the foot 4| is now lowered upon the flask thereby preventing the denture forming material from swelling during the curing or molding thereof, it being understood that at this time the lid need not be clamped down or any exterior pressure applied Also by means of placing the ty-five minutes, the wrench 38 is now operated for gradually forcing the foot downwardly and urging the matrices toward each other, the lid not being clamped to the boiler by means of the links 2! at thistime. The pressure is applied gradually until the matrices cannot be urged towards each other further and the denture is retained in its matrices until it assumes the contour of the latter.

It will benoted that the flask and contents to gether with the cradle may be readily removed from the recess 22 for ascertaining whether or not the two half portions of the flask have been moved towards each other to an adequate extent and, if not, the whole may be replaced for further operation thereon.

Heretofore the treatment of vulcaniterubber and vinyl-resin compositions have been described.

I'I he other herein mentioned denture compositions with the exception of certain phenol-formaldehyde denture preparations are treated as above described for vulcanite preparations.

Some phenol-formaldehyde compositions are treated and cured in conjunction with alcohol, for imparting certain shades or colors to the finished article. The phenol-formaldehyde compositionswhich are not formed of a natural material color may be prepared as above described for vulcanite.

Assuming that the denture'material 84 is a phenol-formaldehyde composition, requiring a preparation thereof in the presence of alcohol an adequate amount of the latter is placed in the recess-chamber 22 prior to placing a flask and denture contents in the chamber. The needle valve being closed, the lid '26 being clamped down, the pet cock 4! being left open until the air is forced out of the recess 22 and alcohol vapor steam starts to pass out of the pet cock 4? which is then closed and at this time a sufficient amount of heat is applied for causing the alcoholic vapor to operate on and properly cure this particular type of denture, it being understood that the wrench may be employed for pressure purposes as may be desired.

It will be noted that during the formation of dentures from any of the above specifically described materials that by means of 1e gauge 53 the pressure within the boiler may be ascertained and the degrees of heat which correspond thereto noted; also the thermometer 46 may be utilized for ascertaining temperatures. Further that an additional check upon and setting of and for the selected degree of heat is provided by the dia phragm valve 59 which, as best shown in Figures 1 and 5, is provided with a graduated scale upon the exterior annular vertical wall 85 of the valve seat member 65, said scale being provided with lines of demarcation indicated at 86 representing degrees of heat, said lines being provided with suitable indicia Bl adapted to register with an indicator 88 mounted upon the stationary bushing 64 of the valve. The valve is manually operable for moving and setting its seat toward or away from the valve 69 a selected distance in accordance with the selected degree of heat desired as rep-resented on the scale of the exterior wall of the chamber 65.

At times when the pressure within the boiler becomes equal to the selected pressure and valve setting the disc 61 of the valve 59 will be moved upwardly as to the central portion thereof by said pressure, thereby causing the valve 69 to move towards its seat 65 and regulate the supply of fuel to the furnace. Should the pressure become less the valve member 69 will move away from its seat for supplying a greater amount of From the foregoing description it is thought" to be obvious that a method and means for forming dentures practiced and constructed in accordance with my invention is particularly well facili-,

tated and adapted for use by reason of the convenience and facility with which it may be assem-, bled and operated and it will also be obvious that my invention is. susceptible of some change. and.

modification without departing from the principles and spirit thereof and for this reason I- do not wish it to be understood as limiting myself to the precise arrangement and formation of the several parts herein shown and specifically de-- scribed in carrying out my invention in practice except as herein claimed.

What is claimed is: V

1. In a device for processing dentures, a boiler for water, a heater for the boiler, a drying and curing chamber in the boiler opening through the top thereof, a cover for the chamber, a valve controlled connectionbetween the steam space in the boiler and said chamber to admit steam to the chamber, a press suspended from the cover in said chamber adapted to carry a flask and a matrix, and three coordinating registering de vices; one device comprising a thermometer carried by the cover and extending down into said drying and curing chamber and into the zone of the flask for accurately indicating the temperature of the matrix, the second device comprising a pressure gauge on the boiler for indicating the pressure of the steam in the boiler forthe relative indication of steam pressure to produce the desired temperature of the matrix, and the third device comprising pressure control means for the heater connected to the boiler for maintaining the necessary heat of the boiler to produce the desired boiler steam pressure and chamber temperature. V

2. In a device for processing dentures, a steam boiler, a drying and curing chamber in the boiler opening through the top thereof, a cover for the chamber, a press suspended from the cover in said chamber adapted to carry a flask and a matrix, and a thermometer carried by the cover and extending down into said drying and curing chamber into the zone of the flask sufiiciently adjacent the matrix and remote from the cover for accurately indicating the temperature in the chamber at the matrix.

3. In a device for processing dentures, a steam boiler, a drying and curing chamber in the boiler, a coverfor the chamber, a press mounted on the cover in said chamber adapted to carry a flask and a matrix, and a temperature indicating device carried by the cover and having a temperature responsive portion disposed in said drying and curing chamber in the zone of the flask and sufliciently adjacent the matrix and remote from the cover for accurately indicating the temperature in the chamber at the matrix.

CLIFFORD M. ANDREWS. 

